Aaron Ramsey was a substitute and entered the action in the 68th minute replacing Santi Cazorla.
The Gunners went on to concede twice, taking them to the brink of elimination but managed to hold on despite the dismissal of Mikel Arteta.
After the final whistle Ramsey showed that he appreciated what a close shave it was for Arsenal and thanked the fans who had made the trip to Italy.
"A poor performance but we're through and now can focus on Saturday. Thanks in particular to the fans who travelled out to Italy," he posted on his Twitter account.
The showing will have provided Arsenal with some questions to answer if they are to go all the way in this season's Champions League, but they remain top of the league and in the hunt for European glory.
image: © wonker